Returns the total remaining energy (in watt-hours) and coupon count from the user's energy coupons that are eligible for use at a specific EVSE. A coupon is considered eligible when it is active, has remaining energy, is within its validity period, and satisfies all restrictions configured on the coupon — including EVSE type (AC/DC), country allowance, partner allowance, and home charge point restrictions. Use this endpoint to check how much coupon-based energy a user can consume before starting a charging session at a given EVSE.